Question

which occurrence would lead you to conclude that lights are connected in a combined circuit?

a. when one bulb burns out, a small section of lights goes out.
b. when one bulb burns out, all the lights go out.
c. when one bulb burns out, all the other lights stay lit.
d. when one bulb burns out, a circuit breaker is tripped.

Explanation:

In a combined (series - parallel) circuit, there are parts in series and parts in parallel. If one bulb (in a series part of the combined circuit) burns out, the current in that series section stops. Since other parallel sections are still intact (assuming the burned - out bulb is not in a main series path that supplies all parallel branches), only a small section (the series section where the bulb was) goes out.

• In a series circuit (not combined), when one bulb burns out, all lights go out (eliminating B).
• In a parallel circuit (not combined), when one bulb burns out, all other lights stay lit (eliminating C).
• A circuit breaker tripping is more related to over - current (not a characteristic of a combined circuit to distinguish it from series/parallel, eliminating D).

Answer:

A. When one bulb burns out, a small section of lights goes out.